Study on properties of coal-sludge-slurry prepared by sludge from coal chemical industry

摘要

Sludge from coal chemical industry is hazardous and difficult to disposal. In this study, a coal chemical sludge was mixed with lignite, coking coal and lean coal to prepare coal-sludge-slurry(CSS) for gasification and combustion. The results showed that the addition of sludge changed CSS from the dilatant fluid to the yield pseudo-plastic fluid. The stability of CSS was observed increasing, while the preparation concentration was decreased at the same viscosity requirement. A combination of BET analysis and EDLVO theory calculation was carried out to study the behavior among particles and water in CSS. Sludge could attract considerable water, increasing the viscosity of slurry. Besides, sludge might connect with coal partides to structure a three-dimensional network which would be destroyed by agitation and then released trapped water, resulting in the pseudo-plasticity of CSS. The network could also prevent the aggregation of particles and improve the stability of slurry. (C) 2020 Elsevier B.V. All rights reserved.